U.S. patent application number 17/171089 was filed with the patent office on 2021-10-14 for sensor system.
The applicant listed for this patent is Hamilton Sundstrand Corporation. Invention is credited to Andrew J. BENN, Grzegorz POPEK.
Application Number | 20210316884 17/171089 |
Document ID | / |
Family ID | 1000005481114 |
Filed Date | 2021-10-14 |
United States Patent
Application |
20210316884 |
Kind Code |
A1 |
POPEK; Grzegorz ; et
al. |
October 14, 2021 |
SENSOR SYSTEM
Abstract
A sensor system for monitoring a motor in an aircraft includes a
wireless sensor arranged to measure a parameter of the motor. The
wireless sensor is further arranged to transmit the parameter to an
external wireless receiver. An energy harvesting unit is provided
that a mass-spring unit arranged to be mechanically coupled to the
aircraft and is arranged to convert mechanical energy arising from
motion of the mass-spring unit to electrical energy, and to supply
said electrical energy to the wireless sensor.
Inventors: |
POPEK; Grzegorz;
(Birmingham, GB) ; BENN; Andrew J.; (Birmingham,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hamilton Sundstrand Corporation |
Charlotte |
NC |
US |
|
|
Family ID: |
1000005481114 |
Appl. No.: |
17/171089 |
Filed: |
February 9, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64D 41/00 20130101;
G01K 1/14 20130101; B64F 5/60 20170101; G01K 7/16 20130101 |
International
Class: |
B64F 5/60 20060101
B64F005/60; G01K 7/16 20060101 G01K007/16; G01K 1/14 20060101
G01K001/14; B64D 41/00 20060101 B64D041/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 9, 2020 |
GB |
2005316.1 |
Claims
1. A sensor system for monitoring a motor in an aircraft, the
sensor system comprising: a wireless sensor arranged to measure a
parameter of the motor, said wireless sensor being further arranged
to transmit said parameter to an external wireless receiver; an
energy harvesting unit comprising a mass-spring unit arranged to be
mechanically coupled to the aircraft; wherein the energy harvesting
unit is arranged to convert mechanical energy arising from motion
of the mass-spring unit to electrical energy, and to supply said
electrical energy to the wireless sensor.
2. The sensor system as claimed in claim 1, wherein the energy
harvesting unit is arranged to be mechanically coupled to the
aircraft's motor.
3. The sensor system as claimed in claim 1, wherein the energy
harvesting unit is arranged to be mechanically coupled to a
component of the aircraft, optionally wherein the component
comprises one or more of the following: a chassis; a fuselage; a
hull; a wing; a structural support; a blade; a landing gear; and/or
a flight control surface of the aircraft.
4. The sensor system as claimed in claim 1, wherein the mass-spring
arrangement has a resonant frequency substantially matched to a
vibration frequency of the aircraft.
5. The sensor system as claimed in claim 1, wherein the wireless
sensor comprises a temperature sensor, and optionally may comprise
a resistive temperature detector, wherein the parameter of the
motor comprises a temperature of the motor.
6. The sensor system as claimed in claim 1, arranged to monitor
multiple parameters, optionally wherein the sensor system is
arranged to monitor multiple parameters of the motor.
7. The sensor system as claimed in claim 6, wherein the wireless
sensor monitors multiple different parameters of the aircraft, and
optionally of the motor.
8. The sensor system as claimed in claim 6, comprising a plurality
of wireless sensors, each wireless sensor being arranged to monitor
one or more parameters of the aircraft, and optionally of the
motor.
9. The sensor system as claimed in claim 1, wherein the mass-spring
unit comprises a magnet and a coil, wherein motion of the mass
spring unit moves the magnet relative to the coil, thereby
generating the electrical energy.
10. The sensor system as claimed in claim 1, wherein the
mass-spring unit comprises a piezoelectric element, wherein motion
of the mass spring unit applies a mechanical stress to the
piezoelectric element, thereby generating the electrical
energy.
11. The sensor system as claimed in claim 1, wherein the
mass-spring unit comprises first and second capacitive plates,
wherein motion of the mass spring unit moves the capacitive plates
relative to one another, thereby generating the electrical
energy.
12. An aircraft comprising a motor and a sensor system, the sensor
system comprising: a wireless sensor arranged to measure a
parameter of the aircraft, said wireless sensor being further
arranged to transmit said parameter to an external wireless
receiver; an energy harvesting unit comprising a mass-spring unit
mechanically coupled to the aircraft; wherein the energy harvesting
unit is arranged to convert mechanical energy arising from motion
of the mass-spring unit to electrical energy, and to supply said
electrical energy to the wireless sensor.
13. A method of monitoring a motor in an aircraft, said method
comprising: converting mechanical energy arising from motion of a
mass-spring unit mechanically coupled to the aircraft to electrical
energy; supplying the electrical energy to a wireless sensor;
measuring a parameter of the motor using the wireless sensor; and
transmitting said parameter to an external wireless receiver.
14. The method as claimed in claim 13, comprising: mechanically
coupling the mass-spring unit to the aircraft's motor; and/or
mechanically coupling the mass-spring unit to a component of the
aircraft, optionally wherein the component comprises one or more of
the following: a chassis; a fuselage; a hull; a wing; a structural
support; a blade; a landing gear; and/or a flight control surface
of the aircraft.
15. The method as claimed in claim 13, comprising: determining a
vibration frequency of the aircraft and substantially matching a
resonant frequency of the mass-spring unit to the vibration
frequency of the aircraft.
Description
FOREIGN PRIORITY
[0001] This application claims priority to United Kingdom Patent
Application No. 2005316.1 filed Apr. 9, 2020, the entire contents
of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] This disclosure relates to a sensor system for use in
aerospace applications, particularly a sensor system for monitoring
a motor in an aerospace application, where a sensor is powered by
harvested energy.
BACKGROUND ART
[0003] In aerospace applications, there may be one or more motors
that are supplied to drive actuators within the aircraft, where the
commutation of these motors is generally controlled by a control
system. These motors are generally supplied with electrical power
by a power converter that supplies electrical power. As will be
understood by those skilled in the art, the power converter
converts power from a source (such as a battery) to a form suitable
for supply to the motor and other systems.
[0004] In order to control commutation of the motor, the position
of the rotor must be `known` by the control system, where the
position information has traditionally been supplied by a sensors,
such as Hall effect sensors.
[0005] Senseless (or `sensorless`) control systems exist in which
voltage and/or current information from the motor can be used to
determine information relating to the position of the rotor. Recent
advancements in senseless control techniques allows for driving the
salient permanent magnet (PM) motors over their full speed range
without significant loss of torque. Such techniques provide for
reduction in the cost of the electric machine, and may remove the
harness required to carry either Hall effect or resolver signals,
which are prone to noise interferences due to close proximity of
the machine feeder cables.
[0006] Unfortunately, in many applications such as aerospace
actuator applications, it is typically necessary to monitor the
temperature of motor windings, e.g. using simple resistive
temperature detectors (RTD). This monitoring requires a low voltage
harness between the power converter and the motor in order to
provide power to the sensors and to return data from the sensor
that conveys the temperature signal from the sensor. This `low
voltage harness` between the motor and the converter can, in some
applications, be up to 30 m long. Those skilled in the art will
appreciate that such a harness has a considerable physical volume
and significant mass associated with it, which is highly
undesirable for aerospace applications.
SUMMARY OF THE DISCLOSURE
[0007] In accordance with a first aspect, the present disclosure
provides a sensor system for monitoring a motor in an aircraft, the
sensor system comprising: a wireless sensor arranged to measure a
parameter of the motor, said wireless sensor being further arranged
to transmit said parameter to an external wireless receiver; an
energy harvesting unit comprising a mass-spring unit arranged to be
mechanically coupled to the aircraft; wherein the energy harvesting
unit is arranged to convert mechanical energy arising from motion
of the mass-spring unit to electrical energy, and to supply said
electrical energy to the wireless sensor.
[0008] This first aspect of the disclosure extends to an aircraft
comprising a motor and a sensor system, the sensor system
comprising: a wireless sensor arranged to measure a parameter of
the motor, said wireless sensor being further arranged to transmit
said parameter to an external wireless receiver; an energy
harvesting unit comprising a mass-spring unit mechanically coupled
to the aircraft; wherein the energy harvesting unit is arranged to
convert mechanical energy arising from motion of the mass-spring
unit to electrical energy, and to supply said electrical energy to
the wireless sensor.
[0009] The first aspect of the disclosure also extends to a method
of monitoring a motor in an aircraft, said method comprising:
converting mechanical energy arising from motion of a mass-spring
unit mechanically coupled to the aircraft to electrical energy;
supplying the electrical energy to a wireless sensor; measuring a
parameter of the motor using the wireless sensor; and transmitting
said parameter to an external wireless receiver.
[0010] Thus it will be appreciated that examples of the present
disclosure overcome the issues outlined above by powering a sensor
using mechanical energy harvested from motion of the aircraft
itself. As the wireless sensor can be powered locally by the energy
harvesting unit, examples of the present disclosure may
advantageously avoid the need for a wiring harness to carry power
(e.g. from a main power converter of the aircraft to the sensor),
which may be located remotely (e.g. of such a main power
converter). Moreover, as the sensor is wireless, there may also be
no need to provide a signal harness. Thus the present disclosure
advantageously allows the benefits of senseless control of the
aircraft's motor to be fully realised.
[0011] Those skilled in the art will appreciate that the term
`aircraft` as used herein extends to any vehicle that can fly,
including but not limited to airplanes, helicopters, airships,
blimps, and powered gliders.
[0012] Avoiding any wiring harness to the sensor that monitors the
motor may also be beneficial due to a reduction in the weight and
volume associated with the wiring harness that would have otherwise
been required without the present disclosure. As outlined above,
conventional wiring harnesses, known in the art per se, may be
around 30 m long, and be undesirably `bulky`.
[0013] The present disclosure may be particularly advantageous for
electric aircraft, i.e. aircraft that have fully electric (e.g.
battery-powered) propulsion systems. The power source (e.g. a
battery), may be located on the aircraft which is beneficial for
weight-distribution purposes, while the wireless sensor can be
provided proximate to the motor elsewhere on the aircraft without
needing to run a wiring harness from that central power source
location to the motor location.
[0014] The aircraft may comprise a power converter that drives the
motor, where there is no electrical connection between the power
converter that drives the motor and the wireless sensor. Such a
power converter may source power from a suitable power source, e.g.
a battery as outlined above or a `conventional` aircraft engine
such as a piston engine or gas turbine.
[0015] Additionally, avoiding the use of a wiring harness may
advantageously help to avoid crosstalk noise between the sensor's
interface signals and feeder cables.
[0016] The energy harvesting unit may be mechanically coupled to
any part of the aircraft that exhibits motion, e.g. that vibrates.
In some examples, the energy harvesting unit may be mechanically
coupled to the aircraft's motor. However, in other examples, the
energy harvesting unit may be mechanically coupled to a different
component of the aircraft, and may be one of the following: a
chassis, a fuselage, a hull, a wing, a structural support, a blade,
a landing gear, or a flight control surface of the aircraft.
[0017] In some examples, the mass-spring arrangement has a resonant
frequency substantially matched to a vibration frequency of the
aircraft. Thus the method may, in some examples, further comprise
determining the vibration frequency of the aircraft and
substantially matching a vibration frequency of the mass-spring
unit to the vibration frequency of the aircraft. It will be
appreciated by those skilled in the art that the term `vibration
frequency of the aircraft` should be understood to mean a frequency
of mechanical vibration that is known to exist within the
aircraft.
[0018] It will be appreciated that there are a number of parameters
of the motor that may be monitored with an appropriate sensor in
accordance with examples of the present disclosure. However, in
some examples, the wireless sensor comprises a temperature sensor,
and optionally may comprise an RTD. Thus, in accordance with such
examples, the parameter of the motor may comprise a temperature of
the motor.
[0019] In some examples, multiple parameters of the motor may be
monitored. A specific wireless sensor may itself monitor multiple
different parameters, and/or the sensor system may comprise a
plurality of wireless sensors, each arranged to monitor one or more
parameters. Similarly, the aircraft may comprise a plurality of
motors, wherein one or more wireless sensors may be provided to
monitor some or all of these motors. In examples in which multiple
parameters are monitored by one or more sensors, these may include
parameters that are not necessarily parameters of the motor, for
example a temperature elsewhere on the aircraft may be monitored,
however in some examples multiple parameters of the motor may be
monitored.
[0020] There are a number of mechanisms to convert the motion of
the mass-spring unit to electrical energy, however in some
examples, the energy harvesting unit may use magnetic,
piezoelectric, and/or electrostatic methods. For ease of
understanding only, the mass-spring arrangement may be seen as
analogous to a `tuning fork`, where the motion of the aircraft, for
example due to vibration from the motor or due to other causes of
such vibration, gives rise to a vibration of the tuning fork (i.e.
of the mass-spring unit).
[0021] With magnetic methods, the motion of the mass-spring unit
causes a magnet to move relative to a coil. Thus the mass-spring
unit may comprise a magnet that moves relative to a coil.
Additionally or alternatively, the mass-spring unit may comprise a
coil that moves relative to a magnet. As the magnet moves relative
to the coil in response to the motion of the mass-spring unit, this
induces an electrical current in the coil, thus providing the
conversion of the mechanical energy of the aircraft to electrical
energy for supply to the wireless sensor. Thus, in some examples,
the mass-spring unit comprises a magnet and a coil, wherein motion
of the mass spring unit moves the magnet relative to the coil,
thereby generating the electrical energy.
[0022] The piezoelectric method, which may be used with some
examples of the present disclosure, involves mechanically coupling
the mass-spring unit to a piezoelectric element. Those skilled in
the art will appreciate that a piezoelectric element is a device
(typically a crystalline solid structure) that generates an
electric charge in response to mechanical stress (e.g. when it is
`squeezed` or `pressed`). Motion of the mass-spring unit causes a
mechanical stress of the piezoelectric element, thereby generating
an electrical charge that can be used to power the wireless sensor.
Thus, in some examples, the mass-spring unit comprises a
piezoelectric element, wherein motion of the mass spring unit
applies a mechanical stress to the piezoelectric element, thereby
generating the electrical energy.
[0023] The electrostatic method, used in accordance with some
examples of the disclosure, makes use of a difference in
electrostatic charge on the mass-spring unit compared to the
electrostatic charge on a `plate` proximate to the mass-spring
unit. The mass-spring unit moves relative to a plate, where the
varying distance or plate overlap causes a change in voltage, i.e.
the arrangement behaves like a capacitor. Thus, in some examples,
the mass-spring unit comprises first and second capacitive plates,
wherein motion of the mass spring unit moves the capacitive plates
relative to one another, thereby generating the electrical
energy.
[0024] A combination of these different types of energy harvesting
techniques may be used.
[0025] The wireless sensor transmits data to the external wireless
receiver via a wireless communication interface. It will be
appreciated that there are a number of wireless communication
interfaces, known in the art per se, that could be used, including
but not limited to Bluetooth.RTM., Wi-Fi.TM., ZigBee.RTM., or a
proprietary wireless communication interface. The wireless
communication interface can be selected depending on, for example,
the wireless communication characteristics that are required (e.g.
frequency, modulation scheme, range, power, noise performance,
security, etc.).
[0026] The Applicant has appreciated that providing a wireless
sensor with electrical energy harvested from mechanical vibration
of the aircraft may be advantageous in other, non-motor related
applications within an aircraft. Thus, when viewed from a second
aspect, examples of the present disclosure provide a sensor system
for monitoring an aircraft, the sensor system comprising: a
wireless sensor arranged to measure a parameter of the aircraft,
said wireless sensor being further arranged to transmit said
parameter to an external wireless receiver; an energy harvesting
unit comprising a mass-spring unit arranged to be mechanically
coupled to the aircraft; wherein the energy harvesting unit is
arranged to convert mechanical energy arising from motion of the
mass-spring unit to electrical energy, and to supply said
electrical energy to the wireless sensor.
[0027] This second aspect of the disclosure extends to an aircraft
comprising a sensor system, the sensor system comprising: a
wireless sensor arranged to measure a parameter of the aircraft,
said wireless sensor being further arranged to transmit said
parameter to an external wireless receiver; an energy harvesting
unit comprising a mass-spring unit mechanically coupled to the
aircraft; wherein the energy harvesting unit is arranged to convert
mechanical energy arising from motion of the mass-spring unit to
electrical energy, and to supply said electrical energy to the
wireless sensor.
[0028] The second aspect of the disclosure also extends to a method
of monitoring an aircraft, said method comprising: converting
mechanical energy arising from motion of a mass-spring unit
mechanically coupled to the aircraft to electrical energy;
supplying the electrical energy to a wireless sensor; measuring a
parameter of the aircraft using the wireless sensor; and
transmitting said parameter to an external wireless receiver.
[0029] It will be appreciated that, in accordance with this second,
broader aspect of the disclosure, the wireless sensor system need
not be arranged to monitor a motor. In some examples, the parameter
may comprise a temperature of a cabin or a hold of the aircraft, as
measured by the wireless sensor. The wireless sensor is powered via
harvested mechanical energy in accordance with the same principles
outlined hereinabove in relation to the first aspect of the
disclosure.
[0030] It will be appreciated that the optional features described
above in relation to examples of the first aspect of the disclosure
apply equally as optional features of the second aspect of the
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Certain examples of the present disclosure will now be
described with reference to the accompanying drawings, in
which:
[0032] FIG. 1 is a block diagram of a prior art motor drive
system;
[0033] FIG. 2 is a block diagram of a motor drive system in
accordance with an example of the present disclosure; and
[0034] FIG. 3 is a block diagram of the wireless sensor unit used
in the motor drive system of FIG. 2.
DETAILED DESCRIPTION
[0035] FIG. 1 is a block diagram of a prior art motor drive system
on an aircraft 102. The aircraft 102, which in this example is an
airplane, has a fuselage portion 103 and a wing portion 105. It
will be appreciated that there are, of course, many other
components to an aircraft, however these simplified `portions` 103,
105 are illustrated broadly for ease of reference.
[0036] In this particular example, the aircraft 102 is an electric
aircraft, and is provided with a power converter 104 located at the
centre of the fuselage portion 103. This power converter 104 draws
power from a battery 107 and converts the battery voltage to
voltages suitable for supply to other systems of the aircraft 102,
including a motor 106. In practice, there may be many motors on the
aircraft 102, however for ease of illustration, a single motor 106
is shown on the wing portion 105 of the aircraft 102. The motor 106
is connected to the power converter via wiring harness 108.
[0037] A temperature sensor 110 is provided on the motor 106 and is
arranged to monitor the temperature of the motor 106 during use.
This sensor 110 is connected to the power converter 104 via a
wiring harness 114, where this wiring harness is used to deliver
electrical power from the power converter 104 to the temperature
sensor 110, and to return temperature data to a receiver 112 within
the power converter 104. The temperature data from the temperature
sensor 110 may be used by the power converter 104 when determining
the voltage and/or current supplied to the motor 106.
[0038] Thus while the motor 106 may be driven by the power
converter 104 without a feedback loop monitoring the motion of the
motor 106, i.e. in accordance with `senseless control` principles,
a wiring harness 114 is nonetheless required in order to supply
power to, and receive data from, the temperature sensor 110,
preventing the prior art system from fully realising the benefits
of senseless control.
[0039] FIG. 2 is a block diagram of a motor drive system on an
aircraft 202 in accordance with an example of the present
disclosure. Many of the components used in the aircraft 202 of FIG.
2 correspond to those in FIG. 1, where reference numerals starting
with a `2` in FIG. 2 correspond to those with reference numerals
starting with a `1` in FIG. 1.
[0040] Unlike in the aircraft 102 of FIG. 1, the aircraft 202 of
FIG. 2 is provided with an energy harvesting unit 216, which is
mechanically coupled to the wing portion 205 of the aircraft 202.
This energy harvesting unit 216 includes a mass-spring arrangement,
where the mass is free to move on the spring in response to motion
of the wing portion 205. The mass-spring arrangement has a resonant
frequency that corresponds to a natural (i.e. resonant) frequency
of the wing portion 205.
[0041] This energy harvesting unit 216 converts mechanical energy
from the motion (e.g. vibration) of the wing portion 205 to
electrical energy, and supplies this harvested electrical energy to
the sensor unit 210.
[0042] A further change from the aircraft 102 of FIG. 1 is that the
sensor unit 210 in the aircraft 202 of FIG. 2 is wireless, i.e. it
conveys the temperature data to the receiver 214 over a wireless
communication interface 218. The wireless communication interface
218 can be selected depending on, for example, the wireless
communication characteristics that are required (e.g. frequency,
modulation scheme, range, power, noise performance, security,
etc.). It will be appreciated that there are a number of wireless
communication interfaces, known in the art per se, that could be
used, including but not limited to Bluetooth.RTM., Wi-Fi.TM.,
ZigBee.RTM., or a proprietary wireless communication interface. The
present disclosure is not limited to any one particular
interface.
[0043] This combination of the use of a wireless sensor unit 210
together with an energy harvesting unit 216, located close to the
wireless sensor unit 210, removes the need for the wiring harness
114 used in the prior art aircraft 102. This cuts down on the
amount of weight associated with the wiring of the aircraft 202,
and results in more physical volume being free. The aircraft 202 of
FIG. 2 may also suffer less crosstalk than the aircraft 102 of FIG.
1.
[0044] FIG. 3 is a block diagram of the wireless sensor unit 210
used in the motor drive system of FIG. 2. The wireless sensor unit
210 comprises a mass-spring unit
[0045] 220, where the mass-spring unit 210 includes a magnetic or
piezoelectric transducer which converts mechanical energy from the
vibrations of the aircraft 202 (in this case the wing portion 205)
to electrical energy (i.e. a voltage).
[0046] This electrical energy is then rectified and conditioned by
electronic circuitry 222. The rectified energy then is being used
to power up the temperature sensor 224, the measurements then being
digitised by an analogue-to-digital converter (ADC) 226. The
digital data corresponding to the measured temperature of the motor
206 is then transmitted via a wireless transmitter 228 to the
wireless receiver 212 in the main power converter 204.
[0047] Thus examples of the present disclosure provide an improved
motor drive system for aircraft in which a wireless sensor is
powered using mechanical energy harvested from motion of the
aircraft itself, thereby avoid the need for any wiring or signal
harnesses to carry power and data between a remote part of the
aircraft and the main power converter. Thus the present disclosure
advantageously allows the benefits of senseless control of the
aircraft's motor to be fully realised.
[0048] While specific examples of the disclosure have been
described in detail, it will be appreciated by those skilled in the
art that the examples described in detail are not limiting on the
scope of the disclosure.
* * * * *